Repair of broken lighting filaments



Aug. 31, 1943. vca. R. BORDEN, JR

"' REPAIR OF BROKEN LIGHTING FILAMENTS Filed March 6', 1945 tibo@INVENTOR. Ory orde/2 Jl? BY f a @4M 1% Patented Aug. 31, 1943 vUNITEDSTATES PAPENT OFFICE REPAIR or BROKEN LIGHTING FILAMENTS Georgey R.Borden, Jr., Blaine'wash.

Anpl'ieetioMareh s, 1943, serial No. 478,2s6

v strumentality of closing the globe filament button and also placingthe main switch such that 4 Claims.

' This invention relates to the art of repairing broken filaments ofelectric light globes, and for its general object aims to provide aheat-responsive method of repairing the break particularly icharacterized in that the same permits the ends of the break to beelectrically connected without fusing the filament wire'.

It is here pointed out that the present method, in common with themethod of Charles J. Sellander described in his U. S. Pat. No. 2,034,960of contact is had between the centerposts and the two terminals markedA. C.A Tracing the wire which leads from the lower side of the plug-inelement, it will thus be seen that this side of the pIug is brought intodirect commotion with one of the two terminals of .the mogul socket, and

March 24, 1936, is one which, without effecting i the sealed conditionof the lam-p, subjects the interior structure to the heating influenceof a stepped-up voltage adapted tov serve a fusing of! flee. There isthis difference, however. The method of the patent essentially placesthe filament under an intensity of heat which is destructive thereto,while my method requires and uses an appreciably lower voltagedeveloping a heat well below critical. To better understand the salientvdistinction between the two procedures,` it is desirable to somewhat;cursorily consider both procedures and by way of comparison point outthat the invention the patent resides in a method functional toaccomplish the repair by bringing the broken filament ends intocontiguity andv fusing together to present a conglomerate bead,necessarily demanding that the potential used for the fusing stepdevelop a temperature condition at or above the melting point of .thefilament.

While the fusing potential is most destructive to the filament life atthe actual point of fusing and and only a limited quantity of new bulbsare madeavailable to civilian users, the method of the patent istherefor of questionable value.

My method, on the other hand, and looking to an elimination of saidobjectionable fusing of the lament metal, recognizes the presence withinthe bulb of an electrically-conductive metal having a fusing point veryappreciably below that of the filament and which, applied as a bridgeacross the broken ends of the filament, functions effectively to closethe filament circuit, the metal in question being that which composesthe terminal Posts and intermediary spiders which support the filament.It may be pointed out, relative to the test line, that the circuit iscompleted by the in rent in consedice of taking the course of leastresistance traversing the globe rheostat line rather than entering theA. C. transformer unit,v

the step-up side of the latter being isolated, moreover, by the fact ofthe voltage regulating switches being open. Resorting, therefor, to abridging of the gap by the use of such available metal having acomparatively low'fusing point and high electric conductivity,I/accomplish, in addition to safeguarding the /lament against thedeleterious effects of a crystallizing heat, the further and importantadvantage of maintaining very close to the exact lighting emciency forwinch the bulb was manufactured.

There is a still further advantage attained from my bridging procedureand which assures an extended period of usage even with lamps which, dueto a momentary arcing across the gap at the time of the break, haddeveloped spot temperatures suiliciently high to have causedcrystallization at the extreme tips of the broken ends. Appreciatingthat my bridging metal in the course of being fused across the gapWillmost usually encase the end extremities, current which is thereafterpassed through the filament is re1- atively isolated from the extremetips in that, following the course of least resistance, the same passesfrom the filament to the bridge at a point removed, if only slightly,from such tips. It becomes self-evident, therefore, that being enabledto `by-pass a known point of weakness and utilizing, for the bypass, ametal of comparatively low resistance to electric current, the generatedheat is comparatively lower in the immediate neighborhood of the break.

As a means of most eiiciently practicing the process, the inventionfurther aims to provide a machineelectrical in nature-which is capableof being used either with direct or alternating current.

Further objects and advantages will appear in the course of thefollowing description and claims, the invention consisting in the newmethod ot repairing burnt-out filaments and in the novel construction,adaptation and combination oi parts for practicing the method, all ofwhich will be set forth with particularity in the following descriptionand in the claims thereto annexed.

In the accompanying drawing:

Figure 1, as a wiring diagram, illustrates the now preferred embodimentof a machine for performing my repair technique; and

Fig. 2 represents a stand-wire assembly of a conventional electric lampand indicates a lighting filament supported thereby and which has beenrepaired inaccordance with the invention, the glass bulb having beendeleted for purposes of maximum clarity in the illustration.

The electric circuits, one A. C. and the other D. C., which I provide inmy machine are believed to 'be re'adily traced Without numericalreference to the various parts employed, these parts being identified bysymbol and each performing their usual function. Novelty is claimed onlyin the sense of combining the parts in a particular manner to accomplishthe specific end of supplying current of controlled intensity to a mogulsocket into which the bulb to be repaired is screwed, the intensityinthe instance of the A. C. circuit being governed by regulatingswitchesindicated as four in number-joined at four tap points to thehigh-voltagetransformer, and in the D. C. circuit being governed by arheostat embodied in a related direct current transformer unit. Thewiring hook-up also includes a test line which, as can be seen from thedrawing, includes a modifying rheostat and a circuit-closing switcharranged to be employed, after a repair operation, to pass line currentthrough the filament.

The electric lamp to which the method of the present invention isadapted is of the usual construction providing an assembly of standwires supporting the filament upon the upper extremities thereof.- Inthe instance of some low-watt lamps, only two such stand wires areprovided, one operating as one and the other as the other of the twoterminal posts for the filament, the latter being carried from the upperend of one post directly to the other post. The two terminal posts arecomposed of an electrically conductive material having a fusing pointbelow the fusing pointof the filament. In the instance of highwattlamps, the terminal posts are customarily augmented by one or morespider arms which have their lower ends anchored by embedding the samein -a glass rod, the said spider arms being similarly electricallyconductive with a fusing point below the fusing point of the filament.Insulated one from another and from the terminal posts, these spiderarms extending upwardly from the supporting rod' and usually terminateat the upper ends in loops which are caused to lie at spaced intervalswithin a relative horse-shoe curve of which the end extremities areoccupied by the upper ends of the terminal posts. The filament, in lampshaving the said spider arms in addition to the terminal posts, is strungsuccessively through the loops of the spider arms from one to the otherterminal post.

Now describing the repair procedure, the lamp is first examined towardascertaining the standing wire which is deemed most desirable as abridging piece, which is to say that the operator selects the terminalpost or spider arm which most readily lends itself to the repair andwhich most usually will be that post or spider arm lying in the closestproximity to the break. Having screwed the lamp into the mogul socket-are.-

ducing insert being employed where a smaller lamp base requires suchtheoperator closes the main switch to complete either an A.' C. or a.

D. C. circuit. according to the source of energyy used,rand passes ahigh-voltage current into the lamp suflicient to cause a jump-sparkacross the lower ends of the terminal posts. From an inspection of thedrawing. Fig. 1, it will be seen that two lines lead to the twoterminals of the mogul socket, and that the jump-spark consequentlyresults within the lamp being repaired whether using the A. C. or the D.C. high-potential circuit as the potential is caused to be stepped-up bythe A. C. hi-voltage transformer or the D. C. hi-voltage transformer, asthe case may be, and which are each operatively joined to these twolines. The effective intensity ofthe stepped-up potential is regulatedin the instance of the A. C. current by the indicated and selectivelyused voltage-regulating switches, and in the instance of the D. C.circuit by the rheostat built into the D. C. transformer, said A. C. andD. C. hi-voltage circuits-being caused to be selectively closed throughthe use of the main switch which is indicated as being of a two-wayknife character movable to the left for closing the A. C.

circuit and movable to the right; for. closing the. the D. C. circuit,the globe lament button being As the open to isolate the test-lineby-pass. heat rises within the lamp, the standing pieces are renderedrelatively pliable and the operator, either by tapping the bulb ormanipulating the mogul socket, causes the selected repair wire to beshifted into such a position yas will permit the free end of the brokenfilament to touch the same. As contact occurs, and bearing in mind thatthe other end of the filament break will be in touching relation to theshifted spider arm as it rides in'the loop of the latter, thehighvoltage current makes a circuit through the filament and thebridging piece of the/repair wire.

The voltage can be now regulated, according to the cross-section of thebridging metal, to readily fuse the latter Without, however, beingsumciently high to develop crystallization within the filament. Repairsare most usually made with the spider arms rather than the terminalposts in that the majority of breaks are found to occur at mid-points asdistinguished from the ends of the filament. However, even with thelarger cross-section which is characteristic of the terminal posts, thesame will fuse under a temperature condition very appreciably below thatWhich will melt the filament.

In Fig. 2 I have illustrated one example of a repairv operation inwhichthe upper extremity s of a spider arm s has been fused as a bridgeto connect the broken ends f' and f" of the filament f, the end f insuch instance having been the part of th filament carried in the loop ofthe spider arm and the end f", being the free end, having been caused tocontact the spider arm at a point somewhat below the loop. The loopitself conglomerates by the fusing heat to form a part of the bridge. Tofurther identify the parts shown in this view, the two terminal posts ofthe stand-Wire assembly and which supply current to the filament aredenoted by p' and p, and the glass rod with its surmounting head andinto which the root ends of the spider arms are embedded is designatedby a.

The method of my invention and structure suitable for practicing thesame is thought to be clear from the foregoing taken With theaccompanying drawing.

What I claim, is: I

1. 'I'he described machine functioning through the instrumentality of astepped-up potential to repair a break in the filament of an electriclamp: comprising the combination of two normally incomplete electriccircuits, one A. C. and the other D. C. arranged to be selectivelyenergized by standard line current and each including, with atransformer unit to perform the stepup oilice Iof the machine, amodifying voltage regulatorA and a switch for closing the respectivecircuits; a. tail socket, common to both circuits, for the reception ofthe lamp to be repaired: and a normally open low-potential test circuitproviding a circuit-closing switch and having functional connection withthe lamp socket.

2. The structure of claim 1 having a pilot light common to each of thesaid circuits and subject to the low-potential of the line energy.

3. The method of repairing a broken filament in an electric lamp of thedescribed character, which is to say a lamp providing an assembly of thelamp and which wires are disposed in spaced relation with the filamentsupported by the upper extremities thereof, the wires being of anelectrically conductive nature insulated one from another and having afusing point below the fusing point of the lament, said methodconsisting in obtaining a contact closure of the filament circuit byselecting one said stand wire proximate lstand wires including the twoterminal posts for" 5to the break and bringing a part of such selectedwire into bridging relation to the break, and then placing a potentialon the terminal posts sufficiently high to fuse the bridge as anintegral part of the circuit without reaching the fusing point of thefilament.

4. The method of repairing a broken filament in an electric lamp of thedescribed character. which is to say a lamp providing an assembly ofstand wires including the two terminal posts for the lamp and one ormore spider arms lying in intervening relation between the terminalposts and wherein the filament is supported by the upper extremities ofsaid stand wires in its carry from one to the other of the terminalposts, said stand wires being of an electrically conductive natureinsulated one from another and having a fusing point below the fusingpoint of the filament, the method consisting in placing a highvoltageload upon the terminal posts of the stand assembly to effectuate an arcdischarge within the lamp rendering the stand wires pliable and then,selecting the stand wire most proximate to the break, manipulating thelamp to cause a portion of the selected wire to bridge itself across thebreak, the impressed potenial which now traverses the filament beingheld to an intensity sufficient to fuse the bridge as an integral partof the filament circuit without reaching the fusing point of thefilament itself.

GEORGE R. BORDEN. JR.

CERTIFIcAT'E `or CORRECTION. Patent No. 2, 528,187. -August; 51, 19115.

GEORGE R. BORDEN, JR.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 1,first column, lineh., beginning with "It may be pointed out,"l strikeout all to and' including "open.' in line 18, same page, second column,and insert the same after "filament." 0n page .2, first column, line456; page 2, first column, line 57, for extending read --extend--g andsecond column, line 27 after l'closxing" strike out "the"; page 5,second column, line 26, claim A l, for "potenial" read potential; andthat the said Letters Patent should be read with this correction thereinthat the same may conform to the record of the case in the PatentOffice.

Signed and sealedthis 26th day of October, A. D. 19).;5.

Henry Van Arsdale, (Seal) Acting Commissioner of Patents.

